Imagine Dragons: "Nothing left to say"

"The shadows on my wall don't sleep, they keep calling me, beckoning...." is personification. He doesn't mean the shadows are really calling to him, he means he is being lured to the darkness. He is becoming drawn to evil, the dark.

Imagine Dragons: "Lay me Down"

"Your eyes are older than the tallest tree you see..."

" Your eyes are older than the tallest tree..." is a simile meaning that they contain a lot more wisdom since they had last seen, and that they themselves look older.